1. Field of the Invention
The present invention relates to a power supply apparatus, and especially relates to a power supply apparatus with variable circuit loop impedance.
2. Description of the Related Art
The inrush current is generated easily when a power supply (or a power conversion apparatus) is just started or a load is just connected to the power supply (or the power conversion apparatus). The power supply (or the power conversion apparatus) is broken easily by the inrush current. Therefore, the power supply (or the power conversion apparatus) usually includes a negative temperature coefficient thermistor for suppressing the inrush current.
However, the resistance of the negative temperature coefficient thermistor is high. The energy of the power supply (or the power conversion apparatus) is wasted when the power supply (or the power conversion apparatus) is in a working mode (no inrush current risk).